They were accused of "working on behalf of a terrorist organisation" and "assisting Islamic State" before they were eventually released on Thursday.

Vice News confirmed the pair had now returned to Britain but they remained "extremely concerned" for their Turkish-based colleague Mohammed Ismael Rasool, who is still in custody.

In a statement, the company said: "Vice News is pleased to confirm two of our journalists, Jake Hanrahan and Philip Pendlebury, have been released from a Turkish prison and have returned to the UK.

"Both are in good health and spirits, but they – and everyone else at Vice News – remain extremely concerned for our third colleague, Mohammed Ismael Rasool, who is still being held.

"Vice News continues to work around the clock with all relevant government and legal representatives to secure his release.

"We call on the Turkish authorities to continue their positive course of action in freeing Jake and Philip, and releasing Rasool immediately."

Before the two journalists were released, the Foreign Office said the UK expected Turkey to uphold its obligations to allow freedom of expression.

A spokesman said: "Respect for freedom of expression and the right of media to operate without restriction are fundamental in any democratic society.

"Turkey is a state party to the European Convention on Human Rights and UN Declaration of Human Rights. We would expect the Turkish authorities to uphold the obligations enshrined in those agreements."

Pendlebury, 30, from Wigan, has filmed in countries including Iraq, Afghanistan and North Korea, while Hanrahan has also written for The Guardian, The Independent, Wired and Rolling Stone Middle East.

Pendlebury's sister Alex took to social media to dismiss the allegations against her brother as "ludicrous" and express her delight that the "nightmare" had come to an end.

She posted on Facebook: "I can't even begin to tell you how happy I am. This has been the most difficult week of our lives but now the nightmare is over!

"I would like to express my gratitude and appreciation to each and every one of you, because without you this wouldn't have happened!